RESEARCH PROGRAM CORE SUMMARY The overarching goal of the Research Program Core (RPC) within the Optimizing Implementation in Cancer Control (OPTICC) Center is to support the rapid development, testing, and refinement of innovative methods to optimizing implementation of evidence-based interventions (EBIs) for cancer control. The approach is to conduct a series of implementation studies, and methods and measurement studies, that address four critical barriers to optimizing EBI implementation in cancer control: underdeveloped methods for barrier identification and prioriti- zation, incomplete knowledge of strategy mechanisms (a requisite for strategy-barrier matching); underutilization of designs for optimizing strategies; and poor measurement of implementation constructs. OPTICC studies will span three optimization stages?identify and prioritize barriers, match implementation strategies to barriers, and optimize implementation strategies through rapid testing?and include measure development. The studies will leverage existing cancer control implementation efforts and respond to emerging priorities of our Implementation Laboratory Partners. We will refine our innovative methods across studies. The rationale is that conducting mul- tiple studies concurrently across the three stages using shared resources will accelerate the speed of knowledge accumulation and method development, with greater efficiency and economy, than conducting independent stud- ies in isolation. The RPC has four specific aims. (1) Advance implementation science in cancer control by con- ducting innovative studies to optimize EBI implementation. Cancer research experts will be supported by Meth- ods Unit Faculty to lead two types of pilot studies that deploy OPTICC methods across the three optimization stages to address Implementation Lab Partners? priorities and overcome the four barriers stymying implementa- tion science in cancer control. (2) Improve measurement and methods in IS by developing reliable, valid, prag- matic measures of implementation constructs and refining innovative methods for optimizing EBI implementa- tion. We will prioritize developing measures and methods that are economical, efficient and approved by stake- holders to ensure widespread uptake. (3) Curate usable knowledge to function as a national consultation re- source. We will develop toolkits, guidance, and workshops leveraging user centered design to ensure our prod- ucts, made publicly available, are ready for deployment. We will organize knowledge in a relational database that will synthesize learnings for the field. (4) Generate innovative methods and chart future directions. We will iterate our current methods with input from OPTICC Study Leads, Methods Unit Faculty, Stakeholder and Sci- entific Advisory Boards, Representatives from our Implementation Lab, and individuals accessing our methods online. We will also develop new methods that leverage technology and advanced analytics. The OPTICC Center has the potential to transform implementation science by delivering new methods to optimize EBI implementation in cancer control that focus on constructing explicit representations of hypothesized causal pathways that con- nect strategies to mechanisms, barriers, and outcomes for planning evaluations and organizing evidence.